Zuercher



March 10, 1964 J. ZUERCHER 3,123,944

BELT CHANGING DEVICE FOR BOWLING LANE SANDING MACHINE Filed July 5, 1962 4 Sheets-Sheet 1 FIG. I

INVENTOR JOHN ZUERCHER gf uh March 10, 1964 J. ZUERCHER BELT CHANGING DEVICE FOR BOWLING LANE SANDING MACHINE Filed July 5, 1962 4 Sheets-Sheet 2 FIG.2

INVENTOR JOHN ZUERCHER :Y

March 10, 1964 J. ZUERCHER 7 3,123,

BELT CHANGING DEVICE FOR BOWLING LANE SANDING MACHINE Filed July 5, 1962 4 Sheets-Sheet 3 INVENTOR JOHN ZUERCHER F Ky W FIG. 3

March 10, 1964 J. ZUERCHER BELT CHANGING DEVICE FOR BOWLING LANE SANDING MACHINE 4 Sheets-Sheet 4 Filed July 5', 1962 INVENTOR JOHN ZUERCHER 2 Kw- United States Patent Ofifice 3,123,944 Patented Mar. 10, 1964 BELT CHANGENG DEVICE FOR BOWLING LANE SANDING MACHINE John Zuercher, Mansfield, Ohio, assignor to American l; Iachine & Foundry Company, a corporation of New ersey Filed July 5, 1962, Ser. No. 207,503 1 Claim. (Cl. 51174) The invention relates to large, belt-type sanding machines, and more particularly to a sanding machine frame structure characterized by improvements which reduce the difficulty involved in changing of the belt.

In a large sanding machine of the type employing a wide abrasive belt of substantial length, an assembly of drums about which the belt travels generally is correspondingly wide and quite heavy. A typical example of a sanding machine having a long, wide belt is one developed particularly for use in the surfacing of bowling lanes. Although the invention will be described in its application to a machine particularly intended for that purpose, it will be understood that the invention may be applied to similar machines wherein the same central problem, discussed hereafter, is involved.

A sanding machine drum assembly may comprise two or three parallel drums having their shafts on both ends supported in bearings carried by the machine frame structure. The frame portion provided for support of the drums generally is associated with other framework providing the main support and housing auxiliary equipment. In order to interchange endless belts the drum supporting framework at one side must be separated from the remaining framework at places where passage of the belt is obstructed. Such breaking of the frame, however, undesirably removes the support from one side of the drum assembly. Therefore, sagging at this one side will occur, possibly to the extent that one or more of the drums rests on the floor and must be lifted manually to permit slipping of the paper therebeneath.

It is the object of the invention to provide a machine framework which is so constructed that when one side thereof is broken to permit paper changing the drums will not drop at this one side but will remain suspended above the floor. Elimination of the effort involved in manually raising the rather heavy drum assembly, of course, represents a significant improvement and advantage.

Briefly, in accordance with the invention, in the con struction of the main frame and the assembly of the entire machine one side of the frame is caused to function on a torque bar principle to suspend the other side during belt changing. That is, the stresses built into one side of the frame act to keep the drums from dropping when the support at the other side of the frame is removed.

Specific details of the invention and further objects of the invention will become evident from the following description thereof, read in conjunction with the accompanying drawings, in which:

FIGURE 1 is a right-hand side elevation of an entire sanding machine having a frame structure embodying the invention;

FIGURE 2 is a partial plan view of the forward part of the machine;

FIGURE 3 is a plan view of the bare framework prior to assembly of the running parts;

FIGURE 4 is a left-hand side elevation of the frame shown in FIGURE 3;

FIGURE 5 is a right-hand side elevation of the frame shown in FIGURE 3; and

FIGURE 6 is a cross section taken as indicated by lines 66 in FIGURE 3, but illustrates the frame when the left-hand side is separated and the weight of the running parts is not applied.

Although an entire machine is shown in FIGURE 1, certain main parts having no direct connection with the invention will be only generally mentioned to provide a general understanding and background. The overall machine framework will be described in detail hereafter. Forwardly, this frame carries a drum assembly comprising a driving drum 2, a cutting or pressure drum 4 and an idler drum 6, and about these drums there is trained a suitable abrasive belt 3. Because the presently illustarted machine is specially constructed for use in the surfacing ofbcwling lanes the length of the rollers 2, 4 and 6 and the width of the belt 8 are sufiicient to cover the 41 to 42 inch width of a standard bowling lane. The main support for the machine is provided by a pair of wheels 10 which are driven from a motor (not shown). Support also is provided re'arwardly by wheels 12, and through the operation of a handwheel 14 the rear of the machine can be raised or lowered relative to the wheels 12. It will be evident, therefore, that the roller assembly is supported mainly by being cantilevered from the rearward frame section, and the operation of handwhe'el 14 serves to raise and lower this roller assembly by pivoting the same about the axis of wheels 10. When the belt 8 is in engagement with the lane or other floor surface, the raising and lowering adjustments of the drum assembly serve, of course, to vary the cutting pressure. The power for driving drum 2 is supplied by a motor 16 and transmitted through belt drives 18 and 22 and a clutch 20. The dust which is produced in the course of sanding is drawn off and collected in a vacuum system generally designated 24. A fire extinguishing system generally designated 25 is provided, being connected to the suction system 24, because of the highly combustible properties of the finishes and dressings used on bowling lanes.

The machine framework on which the aforementioned components are organized comprises essentially a forward and a rearward frame which are interconnected to form a unitary structure. Referring to FIGURES 4 to 6, the rearward frame is a weldment comprising parallel side members 26 and 28 and cross members 30 and 32. A rearward cross member 34 is detachably connected to the side members 26 and 28 and carries a structure 36 adapted to support the machine operators controls. The forward frame comprises parallel side members 38 and 4t) and cross members 42, 44 and 46. These side members and cross members, in both the front and rear frames, comprise either square or rectangular structural steel sections. At the rearward butt end of side member 38 there is welded a plate 48 which forms a lever arm that is connected to the rear frame cross member 32 by bolts 5'0. Welded to the side of member 38 at this end is a plate 52 which is secured to the rear frame member 26 by bolts 54.

When the machine is fully assembled the forward side member at is in alignment with the rearward side memher 2%. The side member 40 is then detachably connected to the front cross member 46 by means of a hinged structure. A bracket 56 welded to the front cross member 46 has a pivot pin 60 on which a plate or strap 58 is mounted. The plate 50 has its free end normally connected to side member 40 by a nut and bolt unit 62 which can be released to permit swinging away of the plate 58. To insure that when the plate 58 is tightened against side member 40 these parts are properly positioned, keys are provided in the form of spheres 64 which nest in aligned holes drilled in the side member 40. The rearward end of side member 40 is detachably connected to the rear frame side member 23 by a plate or strap 66 and releasable nut and bolt units 68. Spheres 70 within aligned holes drilled in these parts provide keys insuring proper mating relationship of the plate 66 against the side members 28 and 40.

It will be understood that the side members 38 and 40 and the cross members 42, 44 and 46 carry the weight of the assembly including drums 2, 4 and 6, and the forces supporting this weight are largely transmitted through the connection between the forward and rear frames. Drum 2 is supported in bearings 72 mounted on the side members 33 and 49. Drum 4 is journalled in bearings mounted on a levelling frame 74 which is shiftably mounted on the cross members 42 and 44 by means of pivot pins 76 representing a central, horizontal pivot axis. The purpose of this pivotal mounting is to carry out automatic levelling of the cutting or pressure drum 4 for the purpose of maintaining cutting in a truely horizontal plane. The necessary corrective levelling adjustments are effected by devices generally designated '78, which operate under the control of an automatic levelling system including bubble-type liquid levels 80. The mechanical arrangement involved in this levelling system is the subject matter of the copending application of Harold W. Martin, Serial No. 207,502, filed July 5, 1962, and entitled Sanding Machine. The idler drum 6 is supported by a bearing 32 carried by the left-hand side member 4!} and a bearing 84 which is vertically movable relative to the right-hand side member 38 by means of a pneumatically operating unit 86. The purpose of the latter feature is to efiect the slight, gradual shifting of the belt 8 back and forth from side to side to produce uniform sanding. Toggle devices 88 are provided to shift the drum 6 forwardly or rearwardly, thereby either to tension the belt 8 or to release the tension during changing of the belt.

During operation of the sanding machine, pressure will be applied to the lower reach of belt 8 in the area of cutting either by the drum 4 directly or through an intermediary platen (the platen 90 being used during the finishing operation but removed for rough cutting). A large percentage of the weight of the forward drum assembly will then be supported directly by the bowling lane or other surface. During the changing of a sanding belt, however, the forward drum assembly is raised above the floor surface by operation of the handwheel 14. The entire weight of the drum assembly is then assumed by the rear machine frame. To remove the belt 8, it is necessary to loosen the nut and bolt units 62 and to swing plate 58 out of the way. Also, it is necessary to loosen nut and bolt units 68 and to remove plate 66. The forward and rear portions of the belt 8 may then be passed through the space provided between forward cross member 46 and side member 4% and the space provided between rearward side member 28 and side member 40. However, it is significant to note that ordinarily, i.e. in the absence of some significant features of the invention which will now be explained, the entire left-hand side of the drum assembly, being now unsupported, would tend to drop. If the cutting or pressure drum 4 would rest on the floor, in order to remove and replace a belt it would be necessary to have one person lift upwardly on the drum assembly while another manipulates the belt.

Referring particularly now to FIGURE 6, it will be explained why the above condition does not occur in accordance with the invention. When the front frame is united with the rear frame by means of bolts 50 and 54, the plates 58 and 66 are not in place. The left-hand side member 40 is raised relative to the right-hand side members 26 and 38, and relative also to the left-hand side member 28, by a distance represented as d in FIG- URE 6. With the left-hand side of the front frame in this raised position, the holes which are drilled to accommodiate bolts 5? are in alignment. The bolts 50 are inserted with the left-hand side of the frame in this raised position and are tightened. The bolts 54 also may be inserted and tightened at this time. In the specifically disclosed form of the invention the distance d will be approximately of an inch. Following this operation, if support of the left-hand side of the front frame is removed, the front frame nevertheless will be suspended in this raised position by virtue of the action of plate or lever arm 48 and bolts 50. As the assembly of the machine proceeds the drums 2, 4 and 6, the automatic levelling mechanism 78, the pneumatic unit 86, etc., are installed. Through the weight of these components the distance 1! will be taken up by sagging of the left-hand side of the front frame 40, until side members 4%) and 28 will be in approximate alignment. In the course of this loading of the front frame, of course, stresses will be developed in the plate or lever arm 43 and the righthand side member 33. Even with the plates 58 and 66 removed, the drum assembly will not drop onto the floor surface. The plates 58 and 66 can then be installed and any misalignment between side members 28 and 40 will be corrected by virtue of the alignment assured by spheres 64 and 7%.

In conclusion, it will now be seen that the objects of the invention are achieved by the frame construction described hereinabove. In the changing of a belt 8 the side plates 58 and 66 can be removed without attendant dropping of the drum assembly, which would require an extra effort to remove the belt from beneath the cutting or pressure drum 4. This is achieved by the imposition of stresses in the frame in the course of its construction which are adequate to suspend the drum assembly above the bowling lane or other floor surface.

It will be understood that various departures from the specifically disclosed embodiment of the invention can be effected without departing from the scope thereof as defined by the following claim.

What is claimed is:

A frame structure for a large sanding machine comprising front and rear frame sections each comprising a pair of parallel side members rigidly interconnected by cross members, said front frame section being adapted to be principally supported from said rear frame section and to carry the main sanding parts, the front and rear side members at one side of the machine being in end-to-end alignment and rigidly interconnected under conditions wherein the front side member at the other side of the machine is slightly above a position of alignment with the rear side member at said other side, whereby the weight of said machine parts carried by said front frame section brings the front and rear side members at said other side into approximate alignment, and means rigidly but detachably connecting the side members at said other side and securing the alignment thereof, the stresses produced in said one side by the loading of said sanding parts being sufficient to prevent substantial dropping of the front side member at said other side upon removal of the last mentioned means for the purpose of interchanging said parts.

References Cited in the file of this patent UNITED STATES PATENTS 1,752,133 Wolgamood Mar. 25, 1930 

